1. Field of the Invention
The present invention relates to a printed circuit board unit and a fan unit incorporated in an electronic apparatus such as a notebook personal computer, for example. In particular, the invention relates to a fan unit including a fan rotating around the rotation axis, and a fan cover defining an inner space for containing the fan.
2. Description of the Prior Art
A fan unit is in general incorporated within a notebook personal computer as disclosed in Japanese Patent Application Publication No. 2001-284863. The fan unit includes a fan cover for containing a fan rotating around the rotation axis. When the fan rotates, air is forced to flow away from the rotation axis in the centrifugal direction. The fan cover serves to guide the air toward a discharge opening. At the same time, an intake opening is defined in the fan cover. Ambient air is introduced inside the fan cover through the intake opening. Airflow is generated along the surface of the printed circuit board.
In general, many electronic components are mounted on the surface of a printed circuit board. Wiring patterns are formed on the surface of the printed circuit board so as to connect the electronic components. A reduction in the size of the notebook personal computer induces a reduction in the size of the printed circuit board. The electronic components and wiring patterns are located on the printed circuit board at a higher density. The tight location of the electronic components and wiring patterns requires an efficient heat radiation from the printed circuit board. The cooling efficiency of the fan should be improved.